tailieunhanh - ARNOLD, K. (1999). Design of Gas-Handling Systems and Facilities (2nd ed.) Episode 1 Part 3

Tham khảo tài liệu 'arnold, k. (1999). design of gas-handling systems and facilities (2nd ed.) episode 1 part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | w O Figure 2-12. Crude oil streams heated with water bath heaters. Courtesy of Smith Industries inc. -Ị f iir OM ỈCMVf-ỉ-WQjri ĩ Heat Transfer Theory 37 q WfOC -TO where qsh sensible heat duty Btu hr w mass flow rate Ib hr c - specific heat of the fluid Btu lb- F Tj initial temperature F T2 final temperature F The specific heat of hydrocarbon vapors and liquids is given by Figures 2-13 and 2-14. In Chapter 6 of Volume 1 it was assumed that c Btu lb-oF for crude oil. It can be seen from Figure 2-13 that this is true for the range of treating temperatures and crude gravities normally encountered in oil treating. Latent Heat The amount of heat energy absorbed or lost by a substance when changing phases is called latent heat. When steam is condensed to SPECIFIC HEAT 8TU LB CFJ Specific of hydrocarbon Liquid . Figure 2-13. specific heats of hydrocarbon liquids. From Holcomb and Brown Ind. Ena. chem. 34 595 1942 reprinted from Process Heat Transfer Kern McGraw-Hill Co. 1950. 38 Design of Gas-Handling Systems anầ Facilities Figure 2 14. Specific heats of hydrocarbon vapors. From Holcomb and Brown Ina. Eng. chem. 34 595 1942 reprinted from Process Heat Transfer Kern McGraw-Hill Co. 1950. water the temperature doesn t change but heat must be extracted from the steam as it goes through a phase change to water. To change water to steam heat must be added. When a substance changes from a solid to a liquid or from a liquid to a vapor the heat absorbed is in the form of latent heat. This heat energy is referred to as latent heat because it cannot be sensed by measuring the .